The Great 2021 Heat Wave: Saturday Updates

I’ve changed the format for today and Sunday…come back to this same link  regularly throughout each day for quick updates as we go through the rest of Saturday.  Newest information FIRST. Remember you can follow me on Twitter: @marknelsenKPTV and Facebook @marknelsenweather

9pm – Final Saturday Evening Update

What a historic day! Portland (and probably Troutdale) broke all-time temperature records…reaching 108 and 109. The final numbers…

And for the region

What’s ahead? In general the forecast hasn’t changed at all. Two more scorching hot days (hotter than today), then a strong marine push Monday evening brings in 70 degree air by 8-10pm west of the Cascades…it’s going to feel glorious. But, of course we have more record-breaking heat first. Tomorrow will be the hottest day south of Portland, due to that marine air arriving Monday midday down there. I expect at least 5 degrees warming from Salem to Eugene tomorrow, setting some all-time records. And at the coastline there will likely be a period from Noon-3pm on the north coast when temperatures soar. Tomorrow will feature conditions I never thought I’d see west of the Cascades. Temperatures to 110 and higher, a dry easterly wind, and nary a cloud in the sky. And keep in mind we’re starting much warmer tomorrow! It’ll take most of the night to get down below 80 in the urban/suburban areas

This will probably break Portland’s all-time warm low temperature. These are bit trickier to do because the weather data is collected for the calendar day (midnight to midnight). If we have a hot spell that ends with a strong marine push in the evening (that will happen Monday)? The late day temperature (close to midnight) could end up being cooler than the warm morning low. I’ve seen it happen in the past. But tomorrow night will be even warmer than tonight so I’m confident we will set this record.

For tomorrow, all models continue to agree that we’ll jump another 3-6 degrees, so I’ve put our forecast high at 112. The new 00z WRF-GFS shows a classic thermal trough from about Medford to Astoria in the afternoon

Easterly wind, although not strong, should be more widespread, and it’ll be windy in the western Gorge tomorrow. I’ve been watering my plants/lawn furiously the past two days in anticipation of that.

Look at those 104 degree highs just about touching the northern coastline beaches…plus 112 or so in the northern Willamette Valley

Then assuming cooling southwest wind doesn’t arrive until 4pm or so Monday, maybe a notch or two warmer. The east and southeasterly flow is very strong through midday Monday overhead and 850mb temps are 31-32 over PDX!

That’s it for now…I’ll be on TV at 10pm with lots more numbers.


Portland officially hit 108 today, hottest on record. More coming up by 9pm or so…dinnertime


It happened! PDX is reporting 107 degrees as the current temperature AND the high so far today. That ties the all-time 107 degree record from 1981 and 1965. I’d say about 1/2 of the time when the high is also the current temp at PDX on a sunny summer day…we end up a degree warmer. Unless the NWS puts out a special statement (seems likely), we’ll know for sure around 7:20pm. It’s quite possible today will go down as the hottest day in Portland’s history. Remember the downtown station has not gone above 107 either and those records go back into the late 1800s.

It’s possibly the 109 at Troutdale is an all-time record, looks like Vancouver is one degree short. A few thoughts

  1. Models nailed this, even better than we did. Even our “high” forecast of 106 has been exceeded. Models have been going more like 107-108 today. Sure enough, we’re doing a little better than Euro showed…which is disturbing for tomorrow.
  2. All models are forecasting between 3 and 6 degrees warming tomorrow as more of a widespread dry/hot easterly wind surfaces. That’s just unreal. Do the math and it’s obvious 110 is probably too low. Working on that now
  3. This has been an exceptional triumph of meteorological modeling. Models forecast all-time records being broken 5-7 days ahead of time.
  4. Power outages are beginning to pop up. About 3,500 PGE customers out


100 at PDX this hour, running 11 degrees above yesterday at 3pm. That puts us on track to hit our 106 degree forecast. Dewpoint is 67…very humid…yuck. Easterly (dry) wind beginning to surface in a few spots. Sure, it’s drier, but hotter. Troutdale and Scappoose jumped to 105 at 3pm! 102 at Rhododendron just below Government Camp is amazing for 1,600′ elevation. Heading toward max temps in the next 3 hours. Once drier air punches down into PDX, expect a temperature spike. Possibly the 107-108 models were forecasting was right. TODAY could be the day we set our all-time record. The drama…

Working on forecast right now and there’s a problem on the north coastline. WRF-GFS pushes easterly flow all the way to beaches and slightly beyond from about Tillamook north tomorrow. 100+ temps may be a possibility just inland from the surf from Long Beach down to Pacific City tomorrow. Maybe Astoria WILL break the all time record you see in the previous post. More later…


Looks like all is proceeding according to plan and no changes to forecast.  Rode my bike around 10-11 a.m.  Tolerable, but turning hot! 

Portland is 91 at noon; that’s plus 10 from yesterday at the same time.

Does that mean we’ll be 105?  Could be, but humidity is still high, dewpoint of 64…yuck.  That tells me the hot atmosphere overhead hasn’t surfaced or “mixed out” yet.  At some point within the next five hours, some drier air from above should surface.  When that happens the temperature will spike, then relative humidity falls.  Notice Yacolt is already 95???  It won’t matter by that time since we’ll be above 100 degrees.  Some other temps around the region are about what I would expect.  

Portland only dropped to 70 last night!  A record for the day, 2nd warmest ever in June.  The other two warmest were during the 2015 heatwave.  Of course that means you just endured the warmest night in 6 years.  Even out here at home in a rural area I only had a low of 63…rare.

Right now pressure gradients around the region are light northerly, or very light easterly across the Cascades.  Wind is light east in the Gorge, but stronger easterlies are arriving on many ridges.  I see Middle Mountain in the Hood River Valley is blowing along with Larch Mtn. and Three Corner Rock Washington.  That’s a sign the blistering hot easterly flow has begun overhead. I haven’t made the forecast yet, waiting to see what happens this afternoon with regard to raising tomorrow’s all-time high temp forecast. Morning GRAF & ECMWF models are the same…forecasting well above 110 both tomorrow and Monday as that dry east wind surfaces both days

That’s it for now.

60 Responses to The Great 2021 Heat Wave: Saturday Updates

  1. JERAT416 says:

    This morning around 7:30 felt like Florida a bit with the temp and humidity, since the numbers are similar. I’m just glad the humidity doesn’t stay that high as the temp climbs here, like it does there.

  2. runrain says:

    PDX has 84° at 9am. If it makes anyone feel better, the 9am temp in Phoenix is 97°.

    • Mr T says:

      Time for Mark to make a Sunday morning edition before it’s noon right? Unless he’s at mass?

  3. W7ENK says:

    OMG, I just stepped outside for a second. The air is so thick, it felt like I stepped into a sauna.

    90 degrees at 8:30am
    RH 68%
    DP 78.0F

    That’s gotta be a record…


  4. lurkingsince’14 says:

    Just dropped in to say this is nuts; never thought I’d see these temps in Oregon. Stay cool all!

  5. Andy says:

    Topped out at 104.2F in my back yard in Albany…I noticed record cold and snow in the Southern Hemisphere in places where winter weather is hitting…some are saying the upcoming winter in the Northern Hemisphere is going to be extreme also…seems to me it’s more than just climate change…the sun is changing and our planets also. Some scientists are perplexed on what to blame it on.

    • Mr T (Stayton Oregon) says:

      What do you think of the Grand Solar Minimum channel on Youtube? Otherwise known as GMS?

      I got shadowbanned last year after the F-I-R-E-S for saying if you’d like we could trade your cold for our heat. Ironically he mentioned a bit about the ‘mega drought’ in the west due to a ‘request’ to show he wasn’t ‘biased’ as claims were. Pfffft.

      Otherwise he does check out other then his spectrums.

      • Andy says:

        I watch several channels…GSM…Watchers…Suspicious Observers…NASA also has many articles…there is a huge amount of info out there, It’s up to the individual what you want to believe. That’s what makes our freedom of info so important.

        • Mr T says:

          Though shadow banning is not freedom especially if it’s over something petty. If a channel owner doesn’t like me he should be a man about it and explain his actions (and possible appeal) or at least come to a mutual understanding.

    • Mr T (Stayton Oregon) says:

      At least GSM is organized in his channels so you can skip to your favorite parts. He does a thing about the sun first segment then I think world weather/climate news that’s hard to get since it’s a non American source then at the end 16 day cast.

      Since it’s a non American source you get a lot of European weather stuff in it he DOESN’T even cover but you can see headlines scroll by.

  6. Tanis Leach says:

    Updated video:

    Technical info (the first one I’m doing on the heat wave):

    The euro model has performed well east of the Cascades, but done only ok west (ran a few degrees too low). With Euro averages 112 and 113 for Sunday and Monday, and GFS being higher (and more accurate with this), I already leant there. I also found the average of all models are 115 Sunday (10-90% being 112-119) and 118 Monday (10-90% being 113-121). Decided to go average as a result, since it has been doing well so far. 850mb temps also support 115 tomorrow and 117 on Monday.

    • Tanis Leach says:

      I’m also embarrassed to say this is take 6. All the other ones were either take 1 or 2.

  7. Gene says:

    I’m a bit intrigued at the reaction on this blog to this record-setting heat. It seems to be universally negative, even though if this was winter and the forecast was for record-setting cold Arctic air, there’d be a lot of excitement. That seems odd to me, because record-setting cold is in its own way every bit as damaging and impactful to people in a negative way as record-setting heat.

    • Tanis Leach says:

      I can’t speak for others, but at least we can still play in snow. Speaking for myself, I can survive with little interruption down to a high of 20 or so. Heat on the other hand I can’t take for the life of me.

      • runrain says:

        The equivalent cold arctic outbreak to this historic heatwave would be below zero temps in Portland. Power outages in THAT would be more deadly, I believe.

        • Jason Hougak says:

          Power outages in the heat would be far more dangerous. If your cold put on more clothes. If your hot, well… isn’t too much to do if you have no power!

  8. Jason Hougak says:

    Record cold in the Southern Hemisphere. Antarctica is 10C colder than normal. Snow and cold in Australia, New Zealand and the Andes.

  9. JERAT416 says:

    Until now, I figured if it were possible possible PDX to go above 107, we would have. I thought it was impossible. However, I suppose even in those 40 years alone, the conditions would have to be just perfect. So if you added up how many weeks of the summer we COULD get to 108 or above, and then how many times we got close, I’ll bet it was hundreds of close calls that just didn’t get there. I guess this makes what’s happening now even more amazing and rare.

  10. Mr T says:

    And certain leaning ‘groups’ still think we are in/heading to an ice age are just NOW becoming aware of the ‘expanding mega drought in the west’ I quote on certain youtube channels. 🤣😲😲.

    PS: Mark needs to fix the comment sign in as the remember me does not work and you have to do things manually and it’s been more and more glitchy the last week.:

    • Jeff says:

      I do agree, that I’ve age opinion is weird, but everyone can have their own opinions, just be a little more respectful that other people have different opinions.

  11. W7ENK says:

    It’s official.

    New all-time record max at PDX today.

  12. tim says:

    My gut feeling tells me this won’t be the last time we see triple digits in portland and seattle this summer after this heatwave.

  13. Worth noting that the more bullish GFS was correct today vs the euro…. So maybe the nightmarish numbers from the GFS Sunday Monday should be taken at face value😳

  14. Evan -- Cedar Mill says:

    Record appears to be broken. Amazing.

  15. W7ENK says:

    PDX 108 at 16:40

    • Lurkyloo says:

      Erik, where’s yer dome? Damn thang only pertects you from the snow, not the heat? Well, I’ll be. That just ain’t right.

  16. Jake says:

    Digital Thermostat on North side of the home in the shade: 106F

    Weather Station above the shed: 106.2F

    Humidity: 21%

  17. 108F pdx. Anticlimactic record given what’s in store next 2 days

  18. Roland Derksen says:

    I’ve noticed a fairly high RH% as well- in the low 60’s. I think we’ll get up to about 95 or 94F- not quite a record for me(the old one of 96 was way back in 1970), but tomorrow could be historic- and Monday.

  19. Mr T (Stayton Oregon) says:

    So how close is the snowline to your house you think? Any snow and ice?

  20. Ken in Wood Village says:

    I just got home from being at the beach for the day (left at 7:30am) Temps started to jump up about 10 miles away from Astoria. When I got to Longview, it was almost 100 on the SUV thermostat. When I got to the I-205/I-84 interchange and I was facing East, the temp jumped to 109. I looked at the Troutdale Airport reading, it said 108 so I think the SUV’s thermostat is correct…lol. This is crazy hot temperatures 🌡😳 it can go away now 🥵

    • Lurkyloo says:

      Didn’t you mean to say it can F-off now? That’s how I feel about all of this. Hate it.

      • Ken in Wood Village says:

        Lmao, I would say a lot more than what you said 🤣😂 if I wanted this HOT temperatures, I would go to Death Valley 💀🤣

  21. Evan -- Cedar Mill says:

    106F at PDX Airport according to NWS. Record could fall today.

  22. Hank says:

    Humidity is now going down in north salem metro, temperatures are about to spike up.

  23. runrain says:

    108° now in Troutdale officially!

  24. Currently 104.5 at my place here in Garden Home.

  25. Evan -- Cedar Mill says:

    Car thermometer 94F at government camp. Insane.

  26. JERAT416 says:

    102 in Tigard as of now….

  27. Evan -- Cedar Mill says:

    111F car thermometer.

  28. Evan -- Cedar Mill says:

    108F on the north side of my southern fence.

  29. runrain says:

    Freezing level over Quillayute yesterday was 18,000’ !

  30. 5OClockCharlie says:

    107 and 108, respectively on two digital thermometers I own. I’m out near 205 and the Stafford area in South Metro. Not sure if these thermometers are wildly inaccurate or my south-facing backyard really is that hot.

  31. runrain says:

    East wind kicked in about 20 min ago in Battleground. 101°

  32. runrain says:

    Looks like Troutdale has hit 100° with 66 dewpoint. Still onshore flow. Amazing.

  33. Joshua Lake Oswego says:

    That southerly wind flip on Monday will feel like heaven. 30 degree drop in 3 hours. Looking like a possible 85 degree low Sunday night. That’s straight up silly.

    • Anonymous says:

      It’s only day 1 of this and I’m very much looking forward to that 30 degree drop in a mater of a few hours.

  34. JohnD says:

    An hour or so ago—coming back from C OR—west of Gov Camp, the car thermo showed 97’ with an e breeze. Then lower 90’s in Sandy. No doubt indicative of the developing changes as Mark notes. 99’ where I now am at the moment near Gateway.

    • Hank says:

      At my weather station in the north part of salem metro is 97.3 degrees 108.5 feels like, 107 degree feels like now its dropping, 106.2 now, 105.5 now, with a 71 degree dew point, 44% humid, which its good the humidity dropped 4% as I was making this.

  35. W7ENK says:


    94 at noon
    +10 for 5pm
    +3 for midsummer sun angle
    = 107 for daytime high

  36. Hank says:

    Forecast for Saturday and Sunday in salem Keizer from all websites I know and models I can get. 106 115 105 110 always undershoots by atleast 3 degrees 102 110 107 115 105 115 102 110 infamously undershoots 104 115 103 115 103 117 103 114
    12z ecmwf 105 115
    12z gfs 104 114
    12z icon 108 117
    12z Norway 106 115
    12z Serbia-mos 104 115
    My forecast, 105 114,
    Salem alltime record 108, June record 105,
    Stay cool out there folks and check in on old people you know, atleast 2 times a day if possible
    And ill be back for the 18z

  37. runrain says:

    Hopefully that dry air gets here soon. Problem is, the higher temps will offset the decrease in dewpoints. Can’t win. Might as well get that record!

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